The present invention relates to a filtering device according to the preamble of claim 1.
Filtering devices constructed according to the preamble of claim 1 are known from the prior art.
In this known type of construction the filtering device consists of three main parts, namely a base part, a cap-shaped and in particular hollow cylindrical filter housing that is detachably connected via its free edge to the base part, and a tubular filter that is arranged in the filter housing and is connected at one front end to the base part and is supported at its other front end in the base region of the filter housing on the latter. The flow of the medium to be filtered may be directed in the tubular filter radially inwardly or radially outwardly. To this end there are provided in the base part two flow-through channels that can be connected to ongoing lines, one of which channels is connected to the interior of the filter, the other channel being connected to the free space between the filter and the circumferential wall of the filter housing.
These known types of constructions have the disadvantage that when removing the filter housing from the base part, for example to check or replace the filter, the filter remains on the base part on account of its particularly tight seal with the said base part and accordingly the filter housing has to be moved axially over the whole length of the filter from the base part before it can be laterally removed. To this end a relatively large installation space or free space is necessary in the vicinity of the filter housing, which is not always available in possible application sites of the filtering device. This is particularly the case with hydraulic drive or transmission units and with construction machinery such as diggers, excavators, loaders, earth-moving equipment, drilling equipment, cranes and similar machinery in which a compact type of construction is required.
The object of the invention is accordingly to provide a filtering device of the type mentioned in the introduction so that installation or dismantling of the filter housing is possible even in tight spatial conditions in the vicinity of the filter housing.
This object is achieved by the features of claim 1. Advantageous modifications of the filtering device are described in the subclaims.
In the filtering device according to the invention a fixing device is provided in order to secure the filter in the base region of the filter housing or to hold the filter in position against a stop means arranged in the base region of the filter.
With both solutions according to the invention the filter housing and the filter together form a moving unit. In this way it is ensured that when the filter housing is removed from the base part the filter remains in position in the filter housing and accordingly the filter housing has to be removed axially from the base part only along a small section, namely has to be removed sufficiently far that the filter is then no longer in contact with the base part. The filter housing and the filter can then be removed laterally as a moving unit. As a result it is possible to install and dismantle the filter housing even in the case of a correspondingly small installation and dismantling space in the axial direction.
Within the scope of the invention the securement of the filter in the base region of the filter housing or a charging of the filter in the direction of the base region of the filter housing may be effected in various ways. In an advantageous modification the filter is tensioned by the force of a spring axially against the base region, wherein the spring may be arranged for example between the base part and the oppositely facing front end of the filter. Another possibility is to provide a fixed connection between the filter and the filter housing, which may be formed for example by a clamping device or a screw arrangement.
The subclaims contain features that lead to simple, small and inexpensively achievable forms of construction, that simplify the installation and dismantling, and furthermore ensure an advantageous flow behaviour and/or filter operation.